Proteases belong to the industrially most important enzymes. For detergents and cleaning agents, they are the longest established enzymes and are contained in virtually all modern, powerful detergents and cleaning agents. They cause the breakdown of protein-containing stains from the item to be cleaned. Among them, proteases of the subtilisin type (subtilases, subtilopeptidases, EC 3.4.21.62) are particularly important, which are serine proteases due to the catalytically active amino acids. They act as unspecific endopeptidases and hydrolyze any acid amide bonds located inside peptides or proteins. Their pH optimum is usually within the distinctly alkaline range. An overview of this family is provided, for example, by the article “Subtilases: Subtilisin-like Proteases” by R. Siezen, pages 75-95 in “Subtilisin enzymes,” edited by R. Bott and C. Betzel, New York, 1996. Subtilases are naturally formed by microorganisms. Special mention should be made of the subtilisins formed and secreted in particular by the Bacillus species as the most important group within the subtilases.
Examples of the proteases of the subtilisin type preferably used in detergents and the cleaning agents are subtilisins BPN′ and Carlsberg, protease PB92, subtilisins 147 and 309, the protease from Bacillus lentus, in particular from Bacillus lentus DSM 5483, subtilisin DY and the subtilases, but no longer the enzymes thermitase, proteinase K and proteases TW3 and TW7 associated with the subtilisins in the narrower sense, and variants of said proteases that have a modified amino acid sequence compared to the starting protease. Proteases are deliberately or randomly modified by methods known from the prior art and are optimized for example for use in detergents and cleaning agents. These include point mutagenesis, deletion or insertion mutagenesis, or fusion with other proteins or protein parts. Correspondingly optimized variants are thus known for most proteases known from the prior art.